This application is based on application No. 10-1999-0018908 filed in the Korean Industrial Property Office on May 25, 1999, the content of which is incorporated hereinto by reference.
(a) Field of the Invention
The present invention relates to hydropolyoxyalkylene oxyalkyl amine compounds useful as a novel fuel oil detergent, more particularly to hydropolyoxyalkylene oxyalkyl amine compounds useful as a novel fuel oil detergent, which can efficiently inhibit both the formation of deposits in the carburetor, injector and intake valve of internal combustion engines and octane number required value increases (ORI) by incorporating the active detergent into the fuel, and a process for preparing the same and a fuel oil composition comprising the same.
(b) Description of the Related Art
It has been known that deposits are formed on the surface of injectors, intake valves, carburetors, etc., of internal combustion engines by the oxidation of the fuel and lubricant oil. These deposits formed in the intake valve block a mixed gas flow which enters a combustion chamber, thereby causing severe drive-ability problems such as misfire and poor acceleration and can significantly increase an automobile""s fuel consumption and produce harmful exhaust pollutants. Furthermore, the deposits formed in a combustion chamber can create mechanical damage to a piston, piston ring, engine head, etc.
Conventionally, an aliphatic amine compound based on long-chained hydrocarbons has been developed and used as a fuel oil detergent in order to inhibit the formation of these deposits. It is disclosed in U.S. Pat. Nos. 3,438,757 and 3,574,576 that hydrocarbyl amines having a molecular weight of 425 to 10,000, preferably 450 to 5,000, are useful as a fuel oil detergent or a lubricating oil dispersing agent of internal combustion engines. Furthermore, it is disclosed in European Patent No. 476,485 A that polybutylaminoalcohol prepared by reacting amine with polybutene epoxide obtained by epoxidizing polybutene is useful as a detergent for the gasoline and as an additive to the lubricant oil. The polybutylaminoalcohol is produced by a nucleophilic substitution reaction of polybutene epoxide with amine.
However, there are problems in that the octane number required value of an engine increases since the above detergents increase the formation of deposits in a combustion chamber, although they have effects of inhibiting the formation of deposits on the surface of the intake valve. Deposits formed on the combustion chamber surface increase the temperature of a combustion chamber by hindering heat transfer between an engine cooling system and the combustion chamber, provoking engine knock by inducing pre-ignition.
Furthermore, a high compression ratio occurs resulting in an engine knock since the volume of the combustion chamber is decreased when deposits are formed on the surface of the combustion chamber. Knocking phenomena can cause damage to pistons, connecting rods, bearings, cam pushrods, etc., if it continues for a long period of time and (it can cause) energy inefficiency.
As described in the above, an octane number required value increase phenomena of an engine occurs when deposits are formed in the combustion chamber, and a fuel having a high octane number should be used so as to prevent the knocking phenomena from occurring in case of an engine having a high octane number required value increase. However, the knocking phenomena can be prevented without using a fuel having a high octane number when the octane number required value increase of the engine is decreased by inhibiting or preventing the formation of deposits in the combustion chamber.
Therefore, it is an object of the present invention to provide a hydropolyoxyalkylene oxyalkyl amine compound as a novel fuel oil detergent which has superior intake valve cleaning effects and inhibits or prevents octane number required value increases.
Furthermore, it is another object of the present invention to provide a process for preparing the hydropolyoxyalkylene oxyalkyl amine compounds.
In order to accomplish the above objects, the present invention provides a hydropolyoxyalkylene oxyalkyl amine compound as a novel fuel oil detergent.
Furthermore, the present invention provides a fuel oil concentrate comprising the hydropolyoxyalkylene oxyalkyl amine compound.
Furthermore, the present invention provides a fuel oil composition comprising the hydropolyoxyalkylene oxyalkyl amine compound and/or concentrate.
Furthermore, the present invention provides a preparation process in which the hydropolyoxyalkylene oxyalkyl amine compound is prepared.
In the following detailed description, only the preferred embodiments of the invention have been shown and described, simply by way of illustration of the best mode contemplated by the inventor(s) of carrying out the invention. As will be realized, the invention is capable of modification in various obvious respects, all without departing from the invention. Accordingly, the description is to be regarded as illustrative in nature, and not restrictive.
The present invention is described in detail as follows.
As a hydropolyoxyalkylene oxyalkyl amine compound, a novel fuel oil detergent of the present invention has a structure such as the following Chemical Formula 1 of which the molecular weight is preferably from 200 to 6,000. 
where m is an integer from 1 to 10, preferably an integer from 1 to 2;
n is an integer from 1 to 80, preferably an integer from 1 to 50;
r and s, each of which can be the same or different, are each independently an integer from 0 to 10, preferably an integer from 0 to 3;
R1 is an alkyl derived from polyolefin having a molecular weight from 200 to 5,000, preferably an alkyl derived from polyolefin having a molecular weight from 200 to 2,500;
R2, R4, and R5, each of which can be the same or different, are each independently hydrogen or alkyl having 1 to 10 carbon atoms, preferably alkyl having 1 to 2 carbon atoms;
R3, as a repetition unit of a polymer chain which can be the same or different between repetition units, is alkylene having 2 to 10 carbon atoms, preferably alkylene having 2 to 5 carbon atoms;
R6 and R9, each of which can be the same or different, are each independently hydrocarbons comprising aromatic chains having 6 to 10 carbon atoms or alkylenes having 2 to 10 carbon atoms, preferably alkylenes having 2 to 6 carbon atoms; and
R7, R8, R10, and R11, each of which can be the same or different, are each independently hydrogen, hydrocarbons comprising aromatic chains having 6 to 10 carbon atoms, alkyls having 1 to 10 carbon atoms, or hydropolyoxyalkylene(oxyalkylene) of the following Chemical Formula 2:
"Parenopenst"R12xe2x80x94O"Parenclosest"p H
where p is an integer from 0 to 80, preferably an integer from 0 to 50; and
R12, as a repetition unit of polymer chains which can be the same or different between repetition units, is a hydrocarbon comprising aromatic chains having 6 to 10 carbon atoms or alkylenes having 2 to 10 carbon atoms, preferably alkylene having 2 to 5 carbon atoms.
A process for preparing a hydropolyoxyalkylene oxyalkyl amine based compound of the present invention consists of reacting hydroxyalkyl amine of the following Chemical Formula 3 with alkyleneoxide having 2 to 10 carbon atoms, preferably 2 to 5 carbon atoms: 
where m is an integer from 1 to 10, preferably an integer from 1 to 2;
r and s, each of which can be the same or different, are each independently an integer from 0 to 10, preferably an integer from 0 to 3;
R1 is alkyl derived from polyolefin having a molecular weight from 200 to 5,000, preferably alkyl derived from polyolefin having a molecular weight from 200 to 2,500;
R2, R4, and R5, each of which can be the same or different, are each independently a hydrogen or alkyl having 1 to 10 carbon atoms, preferably alkyl having 1 to 2 carbon atoms;
R6 and R9, each of which can be the same or different, are each independently a hydrocarbon comprising aromatic chains having 6 to 10 carbon atoms or alkylenes having 2 to 10 carbon atoms, preferably alkylene having 2 to 6 carbon atoms; and
R13, R14, R15, and R16, each of which can be the same or different, are each independently hydrogen, a hydrocarbon comprising aromatic chains having 6 to 10 carbon atoms, an alkyl having 1 to 10 carbon atoms, or an hydroxyalkyl of the following Chemical Formula 4:
xe2x80x94R17xe2x80x94OH
where R17 is a hydrocarbon comprising aromatic chains having 6 to 10 carbon atoms or alkylenes having 1 to 10 carbon atoms, preferably alkylene having 1 to 5 carbon atoms.
Preparation of Hydroxyalkyl Amine
The first step reaction is epoxidation of polyolefin. Polyolefin having a double bond forms oxirane rings by an oxidant which can cause epoxidation, thus becoming polyolefin epoxide. Polyolefin epoxide is prepared from polyolefin having an average molecular weight from 200 to 5,000, preferably from 200 to 2,500.
Polyolefin, as a mixture of molecules having generally different molecular weights, can have one or more branched chains per 6 carbon atoms, preferably one or more branched chains per 4 carbon atoms, and polyolefin having one or more branched chains per 2 carbon atoms is more preferable. These polyolefins can be prepared from olefin having 2 to 6 carbon atoms, preferably olefin having 3 to 4 carbon atoms, and isobutylene or polybutene prepared by reacting a C4 distillate containing isobutylene is most preferable.
These polyolefins have double bonds, and they become polyolefin epoxide when these double bonds form oxirane rings with various oxidants. Oxidants which can be used in the preparation of polyolefin epoxide can be all notified oxidants. Preferable oxidants include hydrogen peroxide, peracetic acid, perbenzoic acid, performic acid, monoperphthalic acid, percamphoric acid, persuccinic acid, pertrifluoroacetic acid, etc., and hydrogen peroxide is more preferable.
Where hydrogen peroxide is employed, an organic acid such as formic acid or acetic acid is additionally added. Particularly, in case of using an organic acid having at least 2 carbon atoms such as acetic acid, it is desirable to add an inorganic acid such as sulfuric acid or phosphoric acid. In this case, hydrogen peroxide is added with a molar ratio of olefin to hydrogen peroxide being 1:0.2 to 1:3.0, preferably 1:0.4 to 1:1.5. The reaction is slow when a molar ratio of olefin to hydrogen peroxide is below 1:0.2, and benefits are reduced when the molar ratio exceeds 1:3.0.
Organic acids are added with a molar ratio of olefin to organic acid being 1:0.1 to 1:1.5, preferably 1:0.2 to 1:1. The rate of reaction is slow when a molar ratio of olefin to organic acid is below 1:0.1, and a side reaction occurs in which ester is produced by the reaction of produced epoxide with organic acid when the molar ratio exceeds 1:1.5.
On the other hand, inorganic acids are added with a molar ratio of olefin to inorganic acid is 1:0.1 to 1:0.6, preferably 1:0.2 to 1:0.4 in case of using organic acids having at least 2 carbon atoms including acetic acid. The rate of reaction becomes slow when a molar ratio of olefin to inorganic acid is below 1:0.1, and a side reaction occurs when the molar ratio exceeds 1:0.6.
The rate of reaction temperature is preferably from 20 to 90xc2x0 C. The reaction becomes slow when the reaction temperature is below 20xc2x0 C., and hydrogen peroxide is decomposed resulting in preparation process difficulties due to high temperature when it exceeds 90xc2x0.
The resulting products are washed with water to remove the oxidant and organic acid, and then are distilled in a vacuum to remove the solvent or are directly distilled in a vacuum without being washed, to obtain polyolefin epoxide.
The second step is an isomerization reaction of the polyolefin epoxide. The polyolefin epoxide produced from the first step reaction has an oxirane ring which is opened by a strong base to form a double bond and to provide a hydroxy polyolefin. Such ring-opening reaction of the alkylene epoxide can also be found in the literature (e.g., Encyclopedia of Chemical Technology, 3rd ed., vol 18, p 633).
In this reaction, common bases publicly known can be used. Preferably, an alkali metal alkoxide or an alkali metal hydroxide obtained by the reaction of an alcohol with alkali metals can be used. More preferably, sodium alkoxide, potassium alkoxide, sodium hydroxide or potassium hydroxide can be used.
The molar ratio of the polyolefin epoxide to the base used in the reaction (with the base) is from 1:0.002 to 1:0.5, preferably from 1:0.005 to 1:0.2. The reaction becomes slow when a molar ratio of the polyolefin epoxide to the base is below 1:0.002, and an additional process for removing bases remaining is needed when the molar ratio exceeds 1:0.5.
The reaction is carried out in 100xcx9c300xc2x0 C., preferably from 140 to 250xc2x0 C. The rate of reaction becomes slow when the reaction temperature is below 100xc2x0 C., and facility corrosion is caused by bases when it exceeds 300xc2x0 C.
Hydroxyl group substituted polyolefin is prepared after removing metallic constituents in the resulting products by washing with water or adsorbing to cation exchange resin, etc. Excess amount of an alcoholic component is distilled off at reduced pressure to provide hydroxypolyolefin.
In the third step reaction, hydroxypolyolefin epoxide is prepared by expoxidizing double bonds in hydroxypolyolefin prepared in the second step reaction in the same way as in the first step reaction.
On the other hand, one or more hydroxyl groups substituted polyolefin epoxide is produced when the second and third step reactions are repeated, and two or more hydroxyl groups substituted polyalkenyl amine (one or more hydroxyl groups substituted polyalkenyl amine is hereinafter referred to as xe2x80x9chydroxyalkyl aminexe2x80x9d) is produced when one or more hydroxyl groups substituted polyolefin epoxide is reacted with the fourth step amine.
The fourth step reaction is the reaction of polyolefin epoxide prepared from the first step reaction or hydroxypolyolefin epoxide prepared from the third step reaction with amine. Polyolefin epoxide or hydroxypolyolefin epoxide can be represented in the following Chemical Formula 5, and hydroxyalkyl amine is produced by the ring-opening reaction of polyolefin epoxide or hydropolyolefin epoxide and amines. Furthermore, the amine is represented in the following Chemical Formula 6. One hydroxyl group exists as hydroxyalkyl amine prepared by omitting the second and third step reactions and reacting polyolefin epoxide produced from the first reaction with amine, and two or more hydroxyl groups exist as hydroxyalkyl amines produced by reacting hydroxypolyolefin epoxide with amine. 
where m is an integer from 1 to 10, preferably an integer from 1 to 2;
R1 is an alkyl derived from polyolefin having a molecular weight from 200 to 5,000, preferably an alkyl derived from polyolefin having a molecular weight from 200 to 2,500; and
R2, R4, and R5, each of which can be the same or different, are each independently hydrogen or alkyl having 1 to 10 carbon atoms, preferably hydrogen or alkyl having 1 to 2 carbon atoms. 
where R6 and R9, each of which can be the same or different, are each independently hydrocarbons comprising aromatic chains having 6 to 10 carbon atoms or alkylenes having 2 to 10 carbon atoms, preferably alkylenes having 2 to 6 carbon atoms; and
R13, R14, R15, and R16, each of which can be the same or different, are each independently hydrogen, hydrocarbons comprising aromatic chains having 6 to 10 carbon atoms, alkyls having 1 to 10 carbon atoms, or hydroxyalkyl of the Chemical Formula 4.
Amines used to prepare hydroxypolyalkenyl amine compounds have one or more basic nitrogen atoms with one or more hydrogen atoms, and they include one or more compounds selected from the group consisting of ammonia, ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetraamine, di(trimethylene)triamine, dipropylenetriamine, tetraethylenepentaamine, 1,2-propylenediamine, 1,3-propylenediamine, dimethylaminopropylenediamine, dipropylenetriamine, 2-aminoethanol, 2-(2-aminoethylamino)ethanol, 1-amino-2-propanol, 3-amino-i-propanol, 4-aminophenol, N-methylamine, N-ethylamine, N-n-propylamine, N-isopropylamine, N-n-butylamine, N-isobutylamine, N-sec-butylamine, N-tert-butylamine, N-n-phentylamine, N-cyclophentylamine, N-n-hexylamine, N-cyclohexylamine, N,N-dimethylamine, N,N-diethylamine, N-di-n-propylamine, N,N-diisopropylamine, N,N-di-n-butylamine, N,N-diisobutylamine, N,N-di(2-hydroxyethyl)amine, N,N-di(3-hydroxypropyl)amine, N, N-di(ethoxyethyl)amine, N, N-di(propoxyethyl)amine, preferably ethylenediamine, diethylenetriamine, triethylenetetraamine or 2-aminoethanol.
The reaction of polyolefin epoxide, hydroxypolyolefin epoxide, or a mixture thereof (hereinafter referred to as xe2x80x9cpolyolefin epoxide, etc.xe2x80x9d) with the amine constituent is generally conducted at a temperature from 100 to 280xc2x0 C., preferably purely conducted or with solvents, at a temperature from 180 to 250xc2x0 C. The rate of reaction becomes slow below 100xc2x0 C. of reaction temperature, and there are no further yield increase effects even when it exceeds 280xc2x0 C. The reaction pressure is generally determined by reaction temperature, presence or absence of the solvent (whether or not solvents exist), and boiling point of the amine constituent.
It is desirable that the molar ratio of the polyolefin epoxide to amine is from 1:1 to 1:10 and that a large quantity of amine is employed to suppress desirably substituting a great deal of polyalkenyl groups for protons of an amine. However, the reactor efficiency is dropped when the molar ratio exceeds 1:10.
The reaction of the polyolefin epoxide and the amine can be carried out in the presence of a catalyst in the state where oxygen does not exist. As a suitable catalyst, a Lewis acid such as trichloroaluminium, trifluoroboron, tetrachlorotitanium or ferric chloride, or a solid catalyst containing a moiety of Lewis acid and Bronsted acid such as alumina, silica, silica alumina and also an organic acid and water, can be used.
Furthermore, the reaction can be conducted with or without a reaction solvent. The solvent is generally used when it is necessary to reduce the viscosity of the reaction product. The solvent if used should be stable and inactive to the reactants and the product. Preferable solvents include aliphatic, aromatic hydrocarbon or aliphatic alcohols.
Reaction temperature can be varied according to whether or not polyolefin epoxide, hydroxypolyolefin epoxide, amine or a catalyst is used. A reaction time is from 1 to 30 hours, preferably from 2 to 20 hours.
When the reaction is completed, the reaction mixture is extracted with a solvent of hydrocarbon-water or hydrocarbon-alcohol-water to remove the residual amine salt or un-reacted amine . The solvent is then distilled and removed under reduced pressure to separate possibly the product. Alternatively, the reaction mixture can be directly distilled off under reduced pressure to remove the residual amine and solvent.
Preparation of a Hydropolyoxyalkylene Oxyalkyl Amine Compound
A hydropolyoxyalkylene oxyalkyl amine compound of Chemical Formula 1 used as a fuel oil detergent of the present invention is prepared by the reaction of hydroxyalkyl amines of Chemical Formula 3 with alkyleneoxides having 2 to 10 carbon atoms, preferably alkyleneoxides having 2 to 5 carbon atoms.
Alkyleneoxide polymerization is initiated from hydroxyl groups in a hydroxyalkyl amine of Chemical Formula 3 and partial primary or secondary amine(s) with catalysts as in the general polyether preparation process by the initiation reaction of the hydroxy compound (Rxe2x80x94OH) or amine compound (U.S. Pat. No. 2,841,479; U.S. Pat. No. 2,782,240; and Kirk-Othmer xe2x80x9cEncyclopedia of Chemical Technologyxe2x80x9d, vol. 18, p616).
A homogeneous polymer like a hydropolyoxypropylene oxyalkyl amine is produced when a single compound such as alkyleneoxide, for example only one type of the compound propyleneoxide, is used. However, a copolymer is easily obtained when a mixture of two or more types, for example a mixture of propyleneoxide and butyleneoxide, is reacted with a hydroxy compound.
Furthermore, a random copolymer is obtained if reactivities of the alkyleneoxide used are each similar while a block copolymer is obtained if a high reactive material such as ethyleneoxide becomes a copolymer. In case of preparing a block copolymer, generally a hydroxy compound is reacted first with alkyleneoxide, and again with another alkyleneoxide, repeatedly.
A hydropolyoxyalkylene oxyalkyl amine compound can be prepared by reacting hydroxyalkyl amine with one or more compounds selected from the group consisting of alkyleneoxides having 2 to 10 carbon atoms, preferably one or more compounds selected from the group consisting of alkyleneoxides having 2 to 5 carbon atoms. Therefore, a hydropolyoxyalkylene chain in a hydropolyoxyalkylene oxyalkyl amine compound of the present invention can be a homogeneous polymer of alkyleneoxide, a random copolymer, or a block copolymer.
Catalysts which are used to prepare a hydropolyoxyalkylene oxyalkyl amine compound include alkaline metal compounds or alkali earth metal compounds, preferably potassium hydroxide, sodium hydroxide, potassium, potassium alkoxide or sodium alkoxide, more preferably potassium hydroxide and sodium hydroxide.
The reaction of hydroxyalkyl amines and alkyleneoxides is conducted without oxygen and with catalysts at a temperature from 60 to 200xc2x0 C., preferably purely conducted or under the existence of solvents, at a temperature from 80 to 150xc2x0 C. The rate of reaction becomes slow when the reaction temperature is below 60xc2x0 C. while a side reaction occurs when it exceeds 200xc2x0 C. The reaction pressure is different according to boiling points of solvents or alkyleneoxide used, and depends on the solvent and alkyleneoxide constituents having a low boiling point.
A somewhat yellow colored hydropolyoxyalkylene oxyalkyl amine compound can be obtained by removing catalysts using adsorbent or ion exchange resin or washing with water and removing unreacted alkyleneoxide and solvents with reduced pressure distillation after the termination of reaction.
Fuel Oil Detergent Concentrate and Fuel Oil Detergent Composition
A fuel detergent of the present invention is used by adding it to hydrocarbon fuels so as to effectively inhibit both the formation of deposits in carburetors, injectors and inlet systems of internal combustion engines as well as octane number required value increases. Concentration of a detergent for maintaining engine cleanliness is determined depending on fuel type, engine type and whether or not other fuel additives exist.
Generally, a hydropolyoxyalkylene oxyalkyl amine compound used as a fuel oil detergent of the present invention is used in a hydrocarbon fuel in a concentration from 50 to 5,000 ppm by weight, preferably in a concentration from 100 to 3,000 ppm by weight. Cleaning effects are minor when the concentration is below 50 ppm by weight while synergy effects of increased addition do not exist when it exceeds 5,000 ppm by weight. A boiling point of a hydrocarbon fuel is preferably between a boiling point of gasoline and that of diesel.
The detergent of the present invention may be formulated as a concentrate, using an inert stable oleophillic organic solvent having a boliling point from about 65 to 205xc2x0 C. Preferably, aliphatic or aromatic hydrocarbon solvents can be used as a solvent in a fuel oil detergent concentrate, and benzene, toluene, xylene, or an aromatic material having a higher boiling point than benzene can be used as the aromatic solvent.
The amount of the detergent constituent hydropolyoxyalkylene oxyalkyl amine compound in the concentrate is from 10 to 90% by weight, preferably from 30 to 80% by weight. Concentration effects are difficult to be expected when the content is below 10% by weight while it is difficult to transfer products due to viscosity increase when it exceeds 90% by weight.
A fuel oil detergent of the present invention can be used in the fuel together with other kinds of ususal additives. Octane number improver such as MTBE, antioxidants, antiknocking agents, a demulsifier, etc., can be used together in gasoline fuel, and they can be used in diesel fuel together with other notified additives such as a pour point depressnat, a flow improver, a cetane number improver, etc.
A fuel oil detergent of the present invention can be employed with a fuel-soluble nonvolatile carrier oil. Such a carrier oil can be selected from a poly(oxyalkylene) derivative, a mineral oil, polyalkene, etc. The carrier oil is considered as to support the inhibition of the formation of deposits when used together with a detergent for the fuel, and can provide a synergistic effect to inhibit the formation of deposits when used together with the fuel detergent of the present invention. The carrier oil is added generally in the amount of 100 to 5,000 ppm by weight, preferably 200xcx9c2,000 ppm by weight relative to the hydrocarbon fuel. The liquid carrier oil can be used additively with the fuel detergent concentrate in the amount of 20xcx9c60% by weight, preferably 30xcx9c50% by weight.